Parasite Medication Parasite Medication For Goldfish?

Parasite medication for goldfish? - parasite medication

My goldfish often shows signs of a tail or another pest, but I can not be sure because it's hard to say. I bought compressed friend Fizz parasite clear tank is in the bottom of the tank when I put one tablet into the tank and my fish is not sick, medicine is evil? I have not done anything yet because I want to, whether it is safe, even when they are sick. Thank you in advance.